How does antifouling work?

Antifouling is a coating for surfaces below the waterline. It limits the attachment and growth of algae, barnacles and other fouling. The mechanism depends on the system.

Biocidal antifoulings

Biocidal products release authorised active substances at the surface. They differ by matrix and wear behaviour:

• Self-polishing antifouling erodes slowly during use, continually exposing an active surface and reducing the build-up of thick old coatings.
• Hard antifouling forms a more abrasion-resistant matrix. Depending on the product, it suits high speeds, regular launching or drying moorings, but remains on the hull.

Speed limit, approved hull materials and fouling level are product-specific. Use biocidal products with care and always read the label and product information before use.

Biocide-free underwater coatings

Biocide-free systems contain no biocidal active substances, but do not all work in the same way:

• Eroding resin coatings such as Seajet 021 EKO renew their surface in a controlled manner.
• Hard two-component coatings such as Seajet 2300 are intended for trailer boats that are regularly hauled out and cleaned.
• Silicone foul-release systems such as Bioclean Eco create a very smooth surface to which fouling attaches less readily.

Cleaning, repair and coating build-up differ considerably. Biocide-free therefore does not automatically mean maintenance-free or suitable for every area.

Why boat use matters

Fouling pressure depends on temperature, nutrients, salinity, berth and time afloat. Hull material, speed, frequency of use and the existing coating also affect selection.

Maintenance without damaging the coating

Inspect the coating after haul-out. Do not aggressively brush biocidal self-polishing coatings in the water because this can remove the active layer. Follow product maintenance instructions and local rules for hard or foul-release systems expressly designed for cleaning.

Use the configurator to find a system for your boat and use. The comparison table compares mechanism, hull materials, speed and coat number.